Jump ship for supervisor reference?

I am planning to apply to grad school in fall 2017. I am aware that most grad schools look for supervisor or educator references.

One of my coworkers just got promoted to unit leader, and she will be the unit leader I report to. It just occurred to me that this coworker is going to be the person I will need to go to when I need a reference written later on. I have already had many problems with her. She is the sort to immediately jump on you and accuse you of things without getting an explanation first.

She is unfortunately a very experienced nurse and she really knows her stuff, but she likes to immediately take over and belittle coworkers whenever something goes down, without even being asked for help. She is particularly fond of rolling her eyes at the new people.

I very seriously doubt she's going anywhere because she's already worked on this unit for more than ten years and she's excited for her promotion. I know anything can happen in a year and a half, but I'd say odds are she's staying put.

Would you all consider it worth changing to another job so you can build a rapport with a different person to get a good reference later, or would you chance staying where you are, hoping for the best?